MIDTERM DECK A Flashcards
What are the four basic pharmacokinetic processes? Hint: MOTIONAcronym: MADE
- absorption
- distribution
- metabolism
- excretion
MEtabolism + excretion = ___________
elimination
The movement of a drug from its site of administration into the blood?
absorption
Drug movement from the blood to the interstitial space of tissues and from there into cells (from blood to target)
distribution
AKA Biotransformation; enzymatically mediated alteration of drug structure.
Metabolism
Movement of drugs and their metabolites out of the body.
excretion.
What are the three ways a a drug can cross cell membranes?
- passage through channels or pores
- passage with aid of transport system
- direct penetration of the membrane itself.
In order to directly penetrate membranes, a drug must be ______ ______ .
Lipid Soluble (lipophilic) p.28Remember: Like dissolves like. If chemical is lipid soluble it can get through lipid membrane
The ____ of absorption is how soon effects will begin. The _____ of absorption helps determine how intense effects will be.
Rate;amount
Rate of dissolution, surface area, blood flow, lipid solubility and pH partitioning are all factors affecting _______.
absorption
The two common routes of drug administration are:
enteral and parenteral.
What is the difference between enteral and parenteral?
enteral is in the GI Tract. Parenteral is anywhere else. Usually means by IV,IM, SC.
Why does the site of drug administration matter? How does it change the effects?
The barriers to absorption associated with each route are different.
Does absorption take place when IV drugs are administered?
No. Absorption is the movement from site of administration INTO the blood. WIth IV, it goes directly into the blood.
What is the advantage to using IV for poorly soluble drugs?
The drugs can be dissolved in large volume of fluid and into the body through IV.
What is the recommended time for injecting a drug via IV? Why?
Over a 1 minute interval at least. It takes 15 second from arm to brain. We would have the chance to see any negative effects before emptying a syringe into the patient. p.33
What should you check for in IV solutions before administering drugs?
Check that drugs are in solution. If cloudy or contains particles, do not use!!!
What is the only barrier to absorption for IM administration?
the capillary wall; The same goes for SC (or SubQ)
What determines the absorption rate of IM administration?
- water solubility
2. blood flow at the site of injection.
If a drug is has poor solubility, even in IV solution, what method of administration can we use?
IM
What is a depot injection?
the administration of a sustained-action drug formulation that allows slow release and gradual absorption, so that the active agent can act for much longer periods than is possible with standard injections. Depot injections are usually given deep into a muscle.
What is a benefit to an IM Depot injection?
Long lasting means fewer injections
If your patient is on coumadin, warfarin or any other anticoagulant, can you give them IM medications?
No. The risk of bleeding is too high.
What are two barriers to absorption in the case of oral administration?
- GI Tract epithelial cells
2. Capillary Wall